The present invention relates generally to the field of sampling air that is exhaled from a patient's lungs and specifically to the field of obtaining a sample of alveolar air containing CO.sub.2 generated from an isotope of carbon; either a stable isotope such as Carbon 13 or a radioisotope such as Carbon 14. Alveolar air is air from the alveoli of the lungs of a person.
Air from the lungs of a person can be used for many different types of testing that would otherwise require the person to undergo an invasive type of therapy. For example, air from the alveoli of a person's lungs can be analyzed for the noninvasive diagnosis of helicobacter pylori (a stomach infection related to a high incidence of ulcers). Crucial to any such testing is the ability to get an accurate sample containing a sufficient volume of air representative of true alveolar air, which is necessary for the specific testing required. The present invention by means of a unique and simple design and method achieves this goal.
The applicant knows of no prior art that either teaches or shows the present invention. For example, U.S. Pat. No. 4,947,861 (Hamilton), an invention developed by the present inventor's father, discloses a structure and method for the noninvasive diagnosis of gastritis and duodenitis that uses a method for sampling the air from the alveoli of a person's lungs by use of an impermeable collecting bag but does not disclose nor suggest either the method or the simple and straightforward structure of the present invention. Likewise other sampling devices of the prior art use techniques that require either that the person or some other person obtain the sample by use of a pump or syringe that was activated manually.
Those methods of sampling can prove to be cumbersome and since different persons or persons may draw the sample in variously different ways such methods do not always produce consistent levels of suction or the reproducible timing required to draw a valid sample. Accordingly, such methods introduce an additional variable that can potentially affect the outcome of a particular test. The present invention by means of its unique and simple design and method eliminates this variable to produce a structure and method that may obtain a reliable sample of the air from the lungs of a person in a safe, accurate, and noninvasive manner.